Low-fat diets that could put your child in peril

Parents who cut out all fat from their children's diets are placing their health at risk, scientists have warned.

Experts have long advised that a moderate intake of 'good' fats - such as olive and sunflower oils - is essential for proper growth and development.

But concerns over the rise in obesity have prompted many families to adopt low-fat regimes.

Now researchers have shown that children burn more body fat than adults for each calorie spent, which means they get rid of it more easily.

They hope this will convince parents not to go to extremes in their battle against the bulge.

The number of fat children has doubled in ten years, with one in four children aged 11-15 now classified as obese - so fat it threatens their health.

The Government is widely expected to miss its target to halt the rise in childhood obesity among under-11s by 2010.

Cutting out all fat is not the solution, however, according to the U. S. researchers writing in the online Nutrition Journal.

Dr John Kostyak and a team from the Pennsylvania State University measured the rate at which whole body fat was used up in ten children aged six to ten, and ten adults.

All were in the healthy, middle range of weight classification for their age and sex.

All the volunteers were given the same typical American diet for three days prior to testing, although adults had larger portions.

The volunteers spent nine hours on three separate days at a low physical activity level, watching movies or reading.

They were tested in a room equipped as a calorimeter - a system to measure heat produced by the body as energy - or under a hood system, to calculate oxygen and carbon dioxide gas levels.

The team also measured the amount of nitrogen in the subjects' urine, and used this to calculate how much fat they oxidised.

The absolute amount of fat burned in a day was similar for both children and adults.

But children burned considerably more fat relative to the amount of energy they used.

The researchers calculated the grams of fat oxidised per calorie of energy expenditure and found it was around 50 per cent higher.

Women and girls used fat at a higher rate than men and boys of a comparable age.

Other studies have shown that dietary fat helps normal growth and includes fat-soluble vitamins vital for the development of eyesight and other organs.

Dr Kostyak said: "Sufficient fat must be included in the diet for children to support normal growth and development."

Jacqui Lowdon, of the British Dietetic Association, said parents needed reminding that fat was good for children - providing it was the right kind.

She said: "Children need the fatty acids and omega 3 found in fat, and fat soluble vitamins A,D and E for growth, development and eyesight.

"There is a risk parents could think that all fat is bad for their children - some years ago we had a phenomenon known as Muesli Belt syndrome where parents went to extremes with food that didn't contain all the nutrients they need."

She said 35 per cent of calories from a healthy diet should come from fat, ideally polyunsaturated and mono-unsaturated fats such as olive and sunflower oils.